├── _config ├── bind9 ├── logrotate ├── named.conf.options ├── named.conf.log └── db.local ├── inc ├── color.sh ├── utils.sh └── log.sh ├── README.md ├── setup └── LICENSE /_config/bind9: -------------------------------------------------------------------------------- 1 | # 2 | # run resolvconf? 3 | RESOLVCONF=yes 4 | 5 | # startup options for the server 6 | OPTIONS="-4 -u bind" 7 | -------------------------------------------------------------------------------- /inc/color.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | # ANSI color codes 4 | IN="\033[36m" # Cyan 5 | ER="\033[31m" # Red 6 | WR="\033[33m" # Yellow 7 | OK="\033[32m" # Green 8 | DB="\033[35m" # Purple 9 | NC="\033[0m" # No color 10 | -------------------------------------------------------------------------------- /_config/logrotate: -------------------------------------------------------------------------------- 1 | /var/log/named/named.log { 2 | daily 3 | missingok 4 | rotate 7 5 | compress 6 | delaycompress 7 | notifempty 8 | create 644 bind bind 9 | postrotate 10 | /usr/sbin/invoke-rc.d bind9 reload > /dev/null 11 | endscript 12 | } -------------------------------------------------------------------------------- /_config/named.conf.options: -------------------------------------------------------------------------------- 1 | options { 2 | directory "/var/cache/bind"; 3 | 4 | forwarders { 5 | 8.8.8.8; 6 | 8.8.4.4; 7 | }; 8 | 9 | allow-query { any; }; 10 | 11 | dnssec-validation auto; 12 | 13 | auth-nxdomain no; # conform to RFC1035 14 | listen-on { any; }; 15 | listen-on-v6 { any; }; 16 | }; 17 | -------------------------------------------------------------------------------- /inc/utils.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | function verify_directory_exists { 4 | 5 | # Check that the directory actally exists 6 | if [ ! -d "$1" ]; then 7 | log "ER" "Expecting directory at '${1}'" 8 | exit 1 9 | fi 10 | } 11 | 12 | function verify_file_exists { 13 | 14 | # Check that the file actally exists 15 | if [ ! -f "$1" ]; then 16 | log "ER" "Expecting file at '${1}'" 17 | exit 1 18 | fi 19 | } 20 | -------------------------------------------------------------------------------- /_config/named.conf.log: -------------------------------------------------------------------------------- 1 | logging { 2 | channel bind_log { 3 | file "/var/log/named/named.log" versions 3 size 5m; 4 | severity info; 5 | print-category yes; 6 | print-severity yes; 7 | print-time yes; 8 | }; 9 | category default { bind_log; }; 10 | category update { bind_log; }; 11 | category update-security { bind_log; }; 12 | category security { bind_log; }; 13 | category queries { bind_log; }; 14 | category lame-servers { null; }; 15 | }; -------------------------------------------------------------------------------- /_config/db.local: -------------------------------------------------------------------------------- 1 | $TTL 120 2 | @ IN SOA DOMAIN_NAME. root.DOMAIN_NAME. ( 3 | 2 ; Serial 4 | 604800 ; Refresh 5 | 86400 ; Retry 6 | 2419200 ; Expire 7 | 604800 ) ; Negative Cache TTL 8 | ; 9 | ns1 IN A DOMAIN_IP 10 | ns2 IN A DOMAIN_IP 11 | * IN A DOMAIN_IP 12 | @ IN NS ns1.DOMAIN_NAME. 13 | @ IN NS ns2.DOMAIN_NAME. -------------------------------------------------------------------------------- /inc/log.sh: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | 3 | function log { 4 | TYP=$1 # ER, WR, OK 5 | MSG=$2 6 | NOW=$(date +"%m-%d-%Y %T") 7 | 8 | case "$TYP" in 9 | "IN") 10 | echo -e "[+] ${IN}${0#\.\/}: [${NOW}] INFO ${MSG}${NC}" 11 | ;; 12 | "ER") 13 | echo -e "[!] ${ER}${0#\.\/}: [${NOW}] ERROR ${MSG}${NC}" 14 | ;; 15 | "WR") 16 | echo -e "[!] ${WR}${0#\.\/}: [${NOW}] WARNING ${MSG}${NC}" 17 | ;; 18 | "OK") 19 | echo -e "[+] ${OK}${0#\.\/}: [${NOW}] SUCCESS ${MSG}${NC}" 20 | ;; 21 | "DB") 22 | echo -e "[?] ${DB}${0#\.\/}: [${NOW}] DEBUG ${MSG}${NC}" 23 | ;; 24 | *) 25 | echo -e "[?] ${DB}${0#\.\/}: [${NOW}] DEBUG Something went wrong when trying to print this error: 26 | >>> TYP(${TYP}), 27 | >>> MSG($MSG), 28 | >>> NOW(${NOW})${NC}" 29 | ;; 30 | esac 31 | } 32 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Out-of-Band DNS Bind Server 2 | 3 | A simple Bind9 server that acts as an open DNS resolver. 4 | 5 | **Note**—for this to work without specifying nameservers 6 | (i.e. `dig A +short foo.bar @ns1.foo.bar`), you would need your domain provider 7 | to have the domain point to your custom domain for example: 8 | 9 | - ns1.foo.bar => `127.127.127.127` 10 | - ns2.foo.bar => `127.127.127.127` 11 | 12 | ## Usage 13 | 14 | ``` 15 | Usage: setup DOMAIN_NAME IP 16 | setup foo.bar 1.1.1.1 17 | setup -h 18 | setup --help 19 | 20 | Options: 21 | -h, --help Print this help message 22 | ``` 23 | 24 | You can then monitor your Bind9 traffic like so: 25 | 26 | ``` 27 | foo@vm13407021391238:~$ sudo tail -f /var/log/named/named.log 28 | 25-Oct-2018 13:22:18.015 queries: info: client @0x7f25082bef80 255.255.255.255.16360047 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 29 | 25-Oct-2018 13:22:20.352 queries: info: client @0x7f25082bef80 255.255.255.255.88#61503 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 30 | 25-Oct-2018 13:22:20.654 queries: info: client @0x7f25082bef80 255.255.255.255.60#18303 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 31 | 25-Oct-2018 13:22:20.903 queries: info: client @0x7f25082bef80 255.255.255.255.60#36200 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 32 | 25-Oct-2018 13:22:21.371 queries: info: client @0x7f25082bef80 255.255.255.255.60#18303 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 33 | 25-Oct-2018 13:22:21.617 queries: info: client @0x7f25082bef80 255.255.255.255.60#60065 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 34 | 25-Oct-2018 13:22:22.080 queries: info: client @0x7f25082bef80 255.255.255.255.60#51886 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 35 | 25-Oct-2018 13:22:22.335 queries: info: client @0x7f25082bef80 255.255.255.255.60#51410 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 36 | 25-Oct-2018 13:22:22.778 queries: info: client @0x7f25082bef80 255.255.255.255.60#61740 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 37 | 25-Oct-2018 13:22:23.030 queries: info: client @0x7f25082bef80 255.255.255.255.60#20153 (foo.bar): query: foo.bar IN A -E(0) (127.127.127.127) 38 | ``` 39 | 40 | Or for something more specific: 41 | 42 | ###### Client 43 | 44 | `dig 12321931-xxe.gbejna.bid` 45 | 46 | ###### Server 47 | 48 | ``` 49 | 25-Oct-2018 14:43:28.202 queries: info: client @0x7f24f8001250 195.158.104.28#58760 (12321931-xxe.foo.bar): query: 12321931-xxe.foo.bar IN A -E(0) (127.127.127.127) 50 | 25-Oct-2018 14:43:28.297 queries: info: client @0x7f24f8001250 195.158.104.28#58760 (12321931-xxe.foo.bar): query: 12321931-xxe.foo.bar IN A -E(0) (127.127.127.127) 51 | 25-Oct-2018 14:43:28.390 queries: info: client @0x7f24f8001250 195.158.104.28#58760 (12321931-xxe.foo.bar): query: 12321931-xxe.foo.bar IN A -E(0) (127.127.127.127) 52 | ``` 53 | 54 | ## Why 55 | 56 | This is very useful when wanting to test for some very hairy vulnerabilities 57 | such as XXE, SSRF and so on. You can inject payloads with random IDs and 58 | subdomains like `8273781123-xxe.foo.bar` and `grep` for it in your logs to 59 | see if the payload ever executed. 60 | 61 | This is also nice to do with Bind9 because: 62 | 63 | - It's super fast, can handle being an open DNS resolver 64 | - DNS outbound traffic is _rarely_ filtered, even if HTTP is 65 | -------------------------------------------------------------------------------- /setup: -------------------------------------------------------------------------------- 1 | #!/bin/bash 2 | # Bind9 Basic Setup 3 | # 4 | # Description: The following shell script sets up Bind9 with basic configuration 5 | # primarily having the server act as an open DNS resolver for certain 6 | # vulnerabilities (i.e. DNSRCE). 7 | # 8 | # Author: Juxhin Dyrmishi Brigjaj 9 | # Version: 1.0.0 10 | # 11 | # Usage: setup DOMAIN_NAME DOMAIN_IP 12 | # setup foo.bid 1.1.1.1 13 | # setup -h 14 | # setup --help 15 | 16 | # Set initial placeholder value for the user domain 17 | DOMAIN_NAME="" 18 | DOMAIN_IP="" 19 | 20 | # Config for /etc/bind/named.conf.log 21 | readonly BIND_NAMED_CONF_LOG=" 22 | " 23 | 24 | # Load utility shells 25 | source "$(dirname "$0")/inc/log.sh" 26 | source "$(dirname "$0")/inc/utils.sh" 27 | source "$(dirname "$0")/inc/color.sh" 28 | 29 | function usage_general { 30 | echo -e " 31 | Usage: ${0#\.\/} DOMAIN_NAME DOMAIN_IP 32 | ${0#\.\/} foo.bid 1.1.1.1 33 | ${0#\.\/} -h 34 | ${0#\.\/} --help 35 | 36 | Provision Bind9 for specified domain name to act as an open DNS resolver. 37 | 38 | Options: 39 | -h, --help Print this help message 40 | " 41 | exit 42 | } 43 | 44 | # Update APT repository and install Bind9 package 45 | function install_dependencies { 46 | log "IN" "Update APT and installing Bind9 package" 47 | apt update 48 | apt install bind9 logrotate -y 49 | } 50 | 51 | # Setup any paths that are required, such as log path 52 | function setup_paths { 53 | log "IN" "Setting up paths and permissions for Bind9 logs" 54 | mkdir -p /var/log/named 55 | chown -R bind:root /var/log/named 56 | chmod -R 775 /var/log/named 57 | } 58 | 59 | # Update all Bind9 (and other) configs to setup 60 | function update_configs { 61 | log "IN" "Updating all Bind9 configurations" 62 | local -r BASE_BIND_PATH="/etc/bind" 63 | 64 | log "DB" "Adding db.local to ${BASE_BIND_PATH}/db.local" 65 | verify_file_exists "${BASE_BIND_PATH}/db.local" 66 | truncate -s 0 ${BASE_BIND_PATH}/db.local 67 | awk -v domain_name="${DOMAIN_NAME}" -v domain_ip="${DOMAIN_IP}" '{ gsub("DOMAIN_NAME", domain_name); gsub("DOMAIN_IP", domain_ip); print $0 }' "${PWD}/_config/db.local" > "${BASE_BIND_PATH}/db.local" 68 | 69 | # Add the domain zone into the list of zones to have permission to answer to queries 70 | echo " 71 | zone \"${DOMAIN_NAME}\" { 72 | type master; 73 | file \"/etc/bind/db.local\"; 74 | }; 75 | " >> "${BASE_BIND_PATH}/named.conf.default-zones" 76 | 77 | 78 | log "DB" "Adding named.conf.options to ${BASE_BIND_PATH}/named.conf.options" 79 | verify_file_exists "${BASE_BIND_PATH}/named.conf.options" 80 | truncate -s 0 "${BASE_BIND_PATH}/named.conf.options" 81 | cat "${PWD}/_config/named.conf.options" > "${BASE_BIND_PATH}/named.conf.options" 82 | 83 | log "DB" "Creating named.conf.log and including it in named.conf" 84 | touch "${BASE_BIND_PATH}/named.conf.log" 85 | cat "${PWD}/_config/named.conf.log" > "${BASE_BIND_PATH}/named.conf.log" 86 | echo "include \"/etc/bind/named.conf.log\";" >> "${BASE_BIND_PATH}/named.conf" 87 | 88 | log "DB" "Setting up lograte for bind" 89 | touch "/etc/logrotate.d/bind" 90 | cat "${PWD}/_config/logrotate" > "/etc/logrotate.d/bind" 91 | 92 | log "DB" "Overwrite Bind9 default file" 93 | cat "${PWD}/_config/bind9" > "/etc/default/bind9" 94 | 95 | log "IN" "Reloading logrotate to take effect on new Bind9 logs" 96 | logrotate -d "/etc/logrotate.d/bind" 97 | 98 | log "IN" "Restarting Bind9 service" 99 | systemctl restart bind9 100 | } 101 | 102 | function main { 103 | install_dependencies 104 | setup_paths 105 | update_configs 106 | } 107 | 108 | # Preflight checks 109 | 110 | # Show usage if no arguments are passed 111 | if [ "$1" = "" ]; then 112 | usage_general 113 | fi 114 | 115 | case $1 in 116 | -h | --help ) usage_general 117 | esac 118 | 119 | DOMAIN_NAME="${1}" 120 | DOMAIN_IP="${2}" 121 | 122 | main 123 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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